I am really sorry to report this - but using the new 1.2.4 and starting a new game still does not mix up ANY ore-fields at all :(
Reverting to 1.2.2 and starting a new game => works as expected.
I am using several mods, some of them adding new ores (like modmash splinter gold, zombies extended core), maybe that is an issue somewhere?
Also (with 1.2.2, no crash with 1.2.4) today I wanted to try out "Vortiks Deep Core Mining" but get crashes like these:
The mod DivOresity (1.2.2) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event DivOresity::on_chunk_generated (ID 12)
DivOresity/control.lua:105: attempt to index field '?' (a nil value)
stack traceback:
DivOresity/control.lua:105: in function <DivOresity/control.lua:87>